Step 1

Cut 12 slits all over beef. Thinly slice the garlic cloves lengthwise into 12 pieces. Insert the garlic pieces into the slits. Let rest at room temperature for 1 hour.

Step 2

Preheat the oven to 475°.

Step 3

In a small bowl, combine the seasoned salt, brown sugar, and black pepper. Brush the roast with olive oil then sprinkle the seasoning mixture all over.

Step 4

Place the onions and thyme sprigs in a large cast-iron skillet. Add the red wine. Place the roast over top and top evenly with the butter. Place in the oven for 15 minutes. Without removing the roast from the oven, reduce the temperature to 275 degrees and cook for 45 to 60 minutes, or until a thermometer inserted into the center of the meat measures 120°. Remove from the oven and transfer the roast to a plate. Tent with foil. Let rest for 15 minutes (or until an internal thermometer in the meat measures around 132° for medium rare.)

Step 5

Meanwhile, remove the thyme sprigs from the skillet. Whisk together the beef stock and flour until smooth. Pour into the skillet and return to the stove on medium heat. Bring to a simmer, then cook for 5 minutes, stirring occasionally until smooth and thickened.

Step 6

Thinly slice the beef and serve with the gravy.